Epicyclic transmission gear



` Dec. 17, 1940. HfKoHN `FPIcYcmc: TRANSMISSION GEAR FledApriI 5, 19;.58 2 Sheets-Sheet l Jaya Jn vez? for Dec. 17, 1940. H, KQHN 2,225,480

EPICYCLIC TRANSMISSION GEAR Filed April 5, 193s 2 sheets-sheet 2 Patented Dec. 17, 1940 UNITED STATES 2,225,480 EPICYCLIC TRANSMISSION GEAR Hans Kohn, Stoetten, Oberamt Geislingen, near Stuttgart, Germany Application April 5, I1938, Serial No. 200,081 In Germany April 7, 1937 16 Claims.

This invention relates to epicyclic transmission gears in which the transmission ratio between the driving and driven shafts is altered A by alteration of the rate of rotation of the planei',` i

carrier and in which the driving torque increases with decreasing speed of the driven shaft.

In accordance with the invention, means are arranged on the planet carrier which vrelieve it more or less completely of torque when the gear is transmitting power. In accordance with the invention, by the coaction of the transmitting and regulating parts, or of the torque acting upon them, an increase in torque as wellv as a continuous alteration in the transmission ratio can be obtained without the provision of a fixed abutment for these parts or their carriers. These parts are instead rotatably or plvotaily mounted on or about one another. To enable the transmission ratio to be altered with a minimum expenditure of power, it is desirable to providea gear train, preferably in the form of an epicyclic gear, the speed of one part of which is adjustable.

. Some of the numerous embodiments of the principle of the invention which are possible are dlagrammatlcally illustrated by way of example in the drawings, in which:

Figure 1 is a longitudinal section through one embodiment of the new transmission gear. A

Figures 2 to 4 are cross sections on lines IIII,

III-III and IV--IV respectively in Figure 1.`

Figure 5 shows another embodiment in longitudinal section. i

In the arrangement of Figures 1 to 4, the power received by the driving shaft I4 is transmitted through the casing I5 to a hollow shaft 20 which has a pinion 2l fixed to it. 'Ihis pinion meshes with the teeth 22' of an annulus 22 mounted at 23' in a carrier 23, called hereinafter a planet carrier, in which ity can rotate about its axis E-E.

The annulus 22 carries coaxially a pinion 24 which meshes with an annulus 25 mounted to rotate freely in the planet carrier 23. A pinion 26' on the driven shaft 28 also meshes with the annulus 25. The driving and driven shaftshave a common axis B-B.

To the annulus 22 is connected a second somewhat larger toothed annulus 22". A pinion 3| referred to hereinafter as the abutment `pinion meshes in the teeth 22"' of the annulus 22".

The spindle 3| of attached to it a toothed wheel 21 which meshes with a pinion 23 mounted in the planet carrier 23 and itself meshing with the regulating pinion the abutment pinion is` mounted in the planet carrier 23 and has firmly 32 on` the regulating shaft 34. The regulating shaft 34 is hollow and lies within the hollow driving shaft 20. The abutment pinion 3| and the toothed wheel 21 are disposed in such a manner relatively to the teeth 22"' of the annu- 5 lus 22 and to the intermediate pinion 23 that they mesh in the part of the teeth 22" which is urged towards the axis B-B (Figure 4).

In order to prevent the pinion 3| from Jamming in the teeth 22" and in order to keep the l0 i teeth in easy running engagement. special abutments are provided which maintain the appropriate distance between these wheels. These abutments are in the form of a roller 3l' on the shaft 3| and a roller 20 on `the driving l5 shaft 20 which bear againstthe track 22* (see Figure 2).

These rollers are also able to compensate to some extent the torque exerted by the driving annulus 22 which is eccentrically mounted in 20 the planet carrier 23. They may, for example, counteract this torque almost entirely leaving only anamount which is convenient or necessary for regulation.

As the toothed wheels 222.22", 3| and the 25 rollers 224, 3|', always make the same movements, reference to the wheels 22', 22", 3| will v in what follows be understood, where the context allows, to include reference to the rollers.

The slight play between the teeth 22" and 30 the teeth of the pinion 3| can also be maintained by mounting the shaft 3| of the two pinionsv 3|l and 21 with a certain amount of play on the planet carrier 23, as illustrated in Figure 4 in which the shaft 3| is mounted in a tongue 35 shaped member 33 which has a certain freedom of movement in the planet carrier 23.

Let us first consider the case in which the planet carrier 23 is stationary. Let it also be assumed, as is illustrated in the drawings, that o the annulus 22' has twice as many teeth as the driving pinion 2| and that the pinions 2l and 26' are of approximately the same size. When the driving shaft 20 makes one clockwise revolution, the annulus 22 is carried round by the 5 driving pinion 2| and makes half a revolution clockwise. The driven shaft 26 which is geared up to it also makes half a revolution clockwise.

If it is now desired to reduce the speed of the driven shaft 26, the planet carrier 23 is ro- 50 tated 'counterclockwisa The annulus 22 is then swung counterclockwise so that in addition to being rotated clockwise by the driving pinion 2|, it also rolls or planetates counterclockwise on the `wheel 2|, i. e. in thesense opposite to that 35 in which the driving shaft rotates. The speed supplement the driving torque This may be done oi' the annulus 22 and thus that of the driven as follows: shaft 26 is slowed down in accordance with the Firmly attaohed to the regulet" 1g Shaft 34 is diierence between these two opposite movements. a easing 31 of a differential gear in which two y 5 When the counterclockwise rotation of the planet pinions 36. 36 are freely journalled at 31. 5 planet carrier 23 becomes so great that the en- These pinions mesh with a sun wheel 35 lixed tire rotary movement which is transmitted by t a shaft passing through the hollow Shaft the driving pinion 2| to the annulus 22 is corn- 34. This shaft which is supported at 50 on the pletely compensated, the annulus remains always driving shaft has at its other end a pinion 5| i0 parallel to itself while it is carried round with Which engages in the teeth 225 of the annulus 10 the planet carrier 23. The annulus 22 thus 22. The planets 36 also mesh with a sun wheel transmits no rotary movement k11,0 the driven v'3B xed to a bevel wheel 39 meshing with a pinion shaft 28. 40. This pinion is ixed to a shaft 4| which is If now the stationary driven shaft 26 is set supported at 42 in the easing l5 and at 43 in a in rotation and its speed gradually increased, sleeve 43 onnthe shaft 50. The speed of the shaft 15 the counterclockwise rotation of the planet car-v 4| Can be altered by o. friction Wheel 44 which is rier 23 is progressively reduced. When the planet displaceable along it and rolls on the stationary carrier 23 is stationary, the first described state Wall |3 The Casing l5 iS Open at l5 t0 make of affairs is reached in which`the speed of the these Darts accessibledriven shaft 25 is half that of the driving shaft The resultant or residual force acting on the 20 20. In orderl to increase the driven speed up to regllltng PHQH 32 and tending t0 rotate it the driving speed, the planet carrier 23 is set ClOkWSe acts through the regulating shaft 34 in rotation clockwise, i. e. in the same direction 0n the derental Casing 37 and iS equally divided as the driving Shaft, The driven shaft, 26 is between the sun wheels 35 and 39 by the pinions completely carriedl round by the shaft 2o, and 36- The force acting on the Wheel 35 is trans- 25 thus the direct drive condition is obtained when ml'ted through the Shaft 50, the pinion 5| and the planet carrier 23 rotates at the speed of the the teeth 22.5 )P0 the annulus 22 which also trans' driving Sheff;` 20. A11 the parte of the gear are mits the driving force of the'pinion 22 through then at rest relatively to one another so that its pinion 24 to the drive. This transmission of 30 the gear behaves like a, continuous shaft" the regulating force by the pinion 5| is favoured 30 In order to alter the transmission ratio, the by the fact that this pinion tends to run more speed of the planet carrier 23 thus has to be rapldly than the annulus 22- altered. In order that this shall not lentail the The dlsplaoomont of the snosion Wheel u along expenditure of any appreciable amount of en the shaft 4| during the pivoting of these parts ergy for this purpose, the parts are so arranged about the mam ams B B may be eecte for 35 that the forces acting on the planet carrier 23 exa-mole' as fouoWS Th? Shaft l is longitud* more or less counteract one another or even muy slottoo' The motion Whoel has oms 4 cancel vthemselves out. Forces which cause rowhich promos through the longltudinol slots "I tation of the planet carrier 23 can'only be transand carry Wlthin the shaft u and not o of o' 40 screwedv spindle 45 which carries outside the uetgngcgnsolxglllfre mounted upon casing a friction Wheel This friction Wheel o one of these parts is the annulus 22, 22m may be brought selectively into engagement with f lls 46 41 which are stationary If the driving shaft rotates clockwise, it -causes one of the two Ws a. counterclockwise torque to act on the planet out which may be displaced to somo extent st 4 carrier 23 (For the t. e being the influence right angles to the axis of the spindle 45. The 5 friction disc 44 may thus be moved selectively which the abutment pinion 3| and the annulus upwards or downwards along the shaft 4|. llafienntlilsen )z2 22 or on the The speed of the annulus 22" or 22 and that of 111er 23 1S the 111111011 '1" 01' its 3011111211 par the friction wheel 4| and the transmission ratio ticuls'rly 1f .that pmi/on (unlike the pinion shown thus be altered. The half of the residual regulatin the drawings) meshes directly with the pm' ing pressure transmitted from the wheel 32- vion 26' instead of through the annulus 25. throu gh the shaft 34 to the differential casing 31 other parts which tend. to rotate the planet and thence to the bevel wheel 39, may be trans- 5,. 11161 23 against the 168611011 Pressue exerted` mitted back to the drive by the friction wheel s by the driving parts are the regula'tmg parts 44 when the wheel39 engages inthe pinion 40.

namely the pinions 3|, 21 and 29 and` the abut- In vmany cases, for example where the power ment Surface '3" in conjuncton Wlth the abuttransmission is high, it may be desirable to make e0 ment Surfaces 22421111 2-' the annulus 22" run at a different speed, in

These Various Darts Which are mounted eC- f particular, a lower speed, than the annulus 22. centrically on the planet carrier can be made so This may be done for example .by means of the that the resultant torque acting upon the planet arrangement illustrated in Figure 5 carrier 23 is always assmall as may be desired. The driving shaft I4 drives the part l5 which In general, it isY not, undesirable that a slight has atoothed annulus |6 in which engages pinions resultant torque should act on the planet carrier I1 mounted for rotation at |1' in a member 20. 23 for the purposefof regulating the transmission y Firmly attached to each pinion |1 is a pinion |8 ratio. In such a case a corresponding torque acts `which meshes with a pinion y||J xed to the reguon the regulating pinion 32. lating shaft 34.

In order that this resultant torque which acts The part 20 to which the driving torque is in the same sense as the driving torquemay not transmitted surrounds the shaft 34 and carries ca'use loss of power and in order at the same time at its end a differential casing 2|0 on which to obtain the maximum equalisation of the part pinions 2|0' are freely mounted. They mesh omwhich the regulating means is to act directly, with a sun wheel 2|D" to which is xed a pinion In; said.' resultant torque is advantageously caused-.to 2|0'". These wheels are free to rotate on the 75 regulating shaft 34. The pinion 2I0"' vmeshes with the teeth 22 of the annulus 22. The driving torque is transmitted from this annulus through the partsk 24,25 and 26' to the driven shaft 26 as has been described with reference to Figure 1.

On their other side, the pinions 2I0' mesh with a sun wheel 2I0 to which is fixed the pinion 2III5.

v These two wheels are free to rotate on thedriving 34 meshes shaft 20. The pinion 2IIIll meshes with the teeth 226 of the annulus 22" which is here completely separated from the annulus 22. By proper selection of the relative sizes of the various pinions and toothed wheels, the speed of the annulus 22" (hereinafter referred to as the regulating an-` nulus) relatively be made smaller in accordance with requirements. 1

As in the case of Figure 1, the abutment pinion 3| which 'is connected through the parts 3|, 21 and 29 to thevpinion 32 on the regulating shaft with the teeth 22 annulus 22". In order totransmit theresultant or residual torque acting on theregulating pinion 32 back to the drive, the pinion I9 on the shaft 34 meshes, as described above, in the pinion IB to the yiriving annulus 22m`ay of, the regulating which meshes with the pinion II which itself meshes with the driving annulus. In this manner, a balance is kept between the pressures acting between the pinions I9, I8 and the pinion I1 and the annulus I so that the drive of the disc I5 is` transmitted through the shaft I1' to the driving part of the Sear.

In many cases, particularly when it is a question of the transmission of relatively small amounts of power, the residual torque acting on the shaft 3l is so small that it is not worth while to transmit it back to the drive. In this case, the parts I5--I9 can be omitted and the part 20 be driven directly. i

In the arrangement of- Figure 5, the regulation of the speed of the planet carrier 23 by the regulating pinion 32 or its shaft 34 can be effected by any desired means for the purpose of altering the speed of that shaft. For example, a clutch, a driving member or "could act upon the shaft 34. For example, an

. ings I5'".

oil clutch, a slipping clutch, an electrical clutch or vbralie or the like connected to the drive could be used or a friction wheel or like drive.

The means illustrated ln Figure 5 for altering the speed of the regulating shaft 34 consistsof an electrical eddy currentbrake." The driving part I5 carries pole shoes I5" which may. be more or less energised by current in the wind- In the gap between the pole shoes I5" runs a disc 34 mounted on the regulating shaft 34. In accordance with the energisation of the poleshoes I5" stronger or weaker eddy currents are produced in the disc 34. of the shaft 34 may thus be increased to any desired extent and this increase can be effectedv continuously from rest up to the speed of the drive I5. i v Y The regulation of the shaft, 34 may also be eected as shown in Figure 4"by the action of a fluid current for example, a current of air by adjustable propeller blades i0 or the like. If the sense of rotation of the driven shaft 2B is to be frequently changed so that the torque acting on the planet carrierisfrequently reversed, it may be convenient to provide the parts mounted on the shafts 3| in duplicate, the two sets of parts lying symmetrically to the left and to the right of thaplane passing through the axes B and E. i

Further alterations'of thegear may also be carried out within the I claim: i 4

1. Cycloid transmission gearing, comprisingin' combination, a drivingshaft, a driven shaft,l a gear carrier mountedfor rotation about at least one of these shafts,a pinion mounted on one of scope of the invention.

these shafts, a cyclic gear meshing with said` 'pinion and rotatably mounted on 'said gear car-l rier, gears interposed between said cyclic gear and said driven shaft, means for regulating the" speed ofsaid gear carrier to change the transmission ratio of the gearing, a member arranged in said gear carrier and adapted -to act thereonin a direction eccentric with respect to at least one of said shafts, another member mounted on said driving"shaft,iand abutting means arranged on said 'carrier so as to bear against said members, whereby to at least torque acting on` said gear' carrier" when said gearing transmits lpower;

2. Cycloid transmission gearing, comprising in combination, a` drivingshaft,-a driven shaft, a

partly counteract the gear carrier mounted for rotation about at least one of these shafts, a pinion mounted on one of these shafts, acyclic gearmeshing with 'said pinion and rotatably mounted on said gear car-J rier,` gears interposed between said cyclic gear i and said driven shaft, meansfor regulating the speed of said gear carrier to change-the transmission ratio of the gearing and abutting means arranged on said gear carrier so as to bear v gearA carrier mounted The speed `and said driven shaft.

"ion and rotatably mounted on against said cyclic gear and a member mounted on said driving shaft, whereby to at least partly counteract the torque acting on said gear carrier when said gearingtransmits power.

3. Cycloid transmission gearing, comprising in combination, a driving shaft, a drivenshaft, a`

for rotation about at least one of these shafts, a pinion mounted on lone of these shafts, a cyclic gear ,meshing withsaid pinion and rotatably mounted on said gear carrier, gears interposed between saidy cyclic gear and said driven shaft, means frregulating the speed Aof said gearcarrier change the transmission ratioof the gearing, rolling means are*A ranged on said cyclic gear, rolling means mount-- ed on said driving shaft and abutting rolling means arranged on said gear carrier so as to bear i against both saidrolling means, whereby to at least partly counteract the'- torque acting on said gear carrier when said gearing transmits power.

4. Cycloid .transmission gearing, comprising-in combination.' a driving shaft, a driven shaft, a gear carrier mounted for rotation about at least one of these shafts, a pinion mounted on one of these shafts, a cyclic gear meshing with said pinion and rotatably mounted on said gear carrier, gears interposed between said cyclic gear means for regulating the speed of said gear carrier to change the transmission ratio of the gearing, a roller track arranged on said cyclic gear. a roller mounted on said driving shaft and an abutting roller arranged for wedgelike engagement with said roller track and said roller. whereby to at least partly counteract the torque acting on said gear carrier when said gearing transmits power. l

` 5. Cycloid transmission gearing, comprising in combination, a driving shaft, a driven shaft, a gear carrier mounted for rotation about at least one of these shafts, a pinion mounted on one of these shafts, a cyclic gear meshing with said pinsaid gear carrier.

gears interposed between said cyclic gear and said said gear carrier-to said roller track -moving ,towards thepoint where said cyclic gear meshes with said pinion, whereby to atleast partly, counteract theV torque acting on `said gear carrier when said gearing` transmits power.y

V6.u The gearing according to claiml 1. wherein they means forlregulating theA speed of said gear carrier are operativelyconnected with the cyclic o gear. l y Y y 7. The gearing according to claim 1, wherein the means fork regulating the speed of said gear o carrier are operatively connected Iwith the cyclic gear by means arranged on the :gear carrier.

8. I,The gearing according to claimv 1, wherein the means for regulating the speedl of Vsaid gear carrier are operatively connected with the cyclic gearv bymeans arranged on the gear carrier, one of said connecting means being arranged to serve asa supportfor theabutting means.`

-9. yThe gearing according to claim 1, wherein the means for regulating the speed of said gear carrier are operativelyconnected with the'cyclic gear by means mounted with some play on and v with respect to the gear carrier.r y f `10. Cycloid transmission gearing, comprising incombination, a ydriving shaft. 4a driven shaft, a'gear carrier mounted for rotation about at least one of -these shafts, a pinion mounted on one of these shafts, a cyclic gear meshing with said pinion androtatably mounted on said gear carrier, gears interposed between said cyclic gear and said driven shaft, means forregulating the speed of said gear carrier to change the transmission ratio of the gearing, means for transmitting back part of the regulating torque to one of said shafts, ,a member arranged in said gear carrier and adapted to act thereon in a direction eccentric with respect to one of said shafts, another member mounted on said driving shaft, and abutting-.means arranged on said gear carrier so as to bear against said members, whereby to be at least partly counteract the torque acting on said gear'carrier when; said 11. Cycloid transmission gearing, comprising in combination, a drivingshaft, a ydriven shaft,

f a gear carrier mounted for rotation about at least onefof these shafts, a piniony mounted on one of gearing transmits power.

l u 2,225,480 -for regulating the speed of` these shafts, a cyclic gear meshing with said pinv ion'and rotatably mounted on said gear carrier, gears interposed between said of said gearcarrier to changethe transmission ratio of the gearing, gearing members connecting a part ofsaid regulating means with either of 'said shafts, a member` arranged in said gear carrier and adapted to act thereon ina direction eccentric with respect to one of said shafts, an'- other member mounted on said driving shaft, and abutting means yarranged on said gear carrier so as to bear .against said members, whereby to at least partly counteract the torque acting on said gear carrierwhen said gearing transmits power.

12. Cyclcid transmission gearing, comprising in combination, a driving shaft, a driven shaft, agear carrier mounted for rotation about at least one of these shafts, a pinion mounted on one of these shafts, a cyclic gear meshing with said pinion and rotatably mounted on said gear carrier, gears interposed between said cyclic gear and said driven shaft, means for regulating the speed of k said gear carrier to change the transmission ratio of the gearing, a differential gear inserted between'partsl of said regulating means,v a part of said differential gear being operatively connected with said cyclic gear, a member arranged in said gear carrier and adapted to act thereon in a direction eccentrill with respect to one of `said shafts, another member mounted on said driving shaft, and abutting means arranged on said gear carrier so as to bear against said members, whereby to at least partly counteract the torque acting on said gear carrier when said gearing transmits power.`

13. The cycloid transmission gearing according to claim 1, wherein the cyclic gear is provided as an annulus having inside gearing.

14. The cycloid transmission gearing according to claim 1, wherein the cyclic gear is provided on its inside a roller 15. The cycloid transmission gearing according to claim 1, wherein all parts enumerated in said claim with the exception of the two shafts are rotatably mounted on rotary parts.

16. The cycloid vtransmission gearing according to claim l, wherein fixed bearings are provided only for the two shafts.

HANS KOHN.

cyclic gear and said driven shaft, means for regulating thespeed 

